Numerous sealant compositions are known in the literature. One of the basic patents in this field is Harlan, U.S. Pat. No. 3,239,478, which shows combinations of styrene-diene block copolymers with tackifying resins and the like to produce a wide variety of sealants and adhesives. Further, it is known that butyl rubbers can be used in a variety of adhesives, sealants and coatings. It has been known that these butyl rubber compounds do not adhere well to polar substrate since the butyl rubber does not form strong chemical bonds to polar substrates.
U.S. Pat. No. 4,007,311, also issued to Harlan, recognized this phenomenon and provides a sealant composition which improves the adhesive qualities of the base block copolymer to polar substrates. This composition covers a base formulation which comprises 5 to 50 weight percent of a block copolymer, to which had been grafted a polymer of an acrylic ester, and from 95-50 weight percent of a non-modified polymer, e.g. polyurethanes, block copolymers, etc. The base copolymer was applied to the substrates in a solvent solution.
U.S. Pat. No. 4,578,429, issued to Gergen et al, describes hydrogenated block copolymers to which are grafted unsaturated, carboxylic acid containing monomers that are non polymerizable or slowly polymerizable. These modified block copolymers were expected to improve the adhesion of the block copolymers to substrates when used in adhesives, sealants, and coatings, although no examples were given of such uses.